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POPULAR ECONOMIC BOTANY. 



Several Gums were omitted from the chapter on those 

 products, because their use was solely medicinal ; they will 

 now therefore be mentioned. 



Gum AsAFGETiDA. — A gum-resin which exudes from in- 

 cisions made in the root of Ferula AmfcEtida (Nat. Ord. 

 Umhellifera) . 



Much learned discussion has taken place upon the pro- 

 bability of this plant being in use amongst the ancients 

 under the name of laser, which it is supposed has been 

 changed to asa, or, as it is called by Avicenna, assa. 



This Ferula is a native of Persia ; it has very large tap- 

 roots, similar to but much larger than the common parsnep. 

 In order to obtain the gum-resin the cultivators remove the 

 earth from the upper part of the root, and then cutting off 

 the crown, from this excision the gum-resin oozes as a 

 milky juice, which however rapidly changes colour and 

 hardens upon exposure to the air ; it is scraped off from 

 time to time; and when fully hardened in lumps, it has a 

 red colour and disagreeable smell, resembling garlic. About 

 3000 lbs. were imported in 1852. Usually it is in lumps, 

 or run in one mass into a case ; sometimes it is in tears, 

 which are yellowish-white, and varying in size from a pea 

 to a walnut. 



